Provided by: libglib-perl_1.326-1build1_amd64 
NAME
Glib::Object - Bindings for GObject
DESCRIPTION
GObject is the base object class provided by the gobject library. It provides object
properties with a notification system, and emittable signals.
Glib::Object is the corresponding Perl object class. Glib::Objects are represented by
blessed hash references, with a magical connection to the underlying C object.
get and set
Some subclasses of "Glib::Object" override "get" and "set" with methods more useful to the
subclass, for example "Gtk2::TreeModel" getting and setting row contents.
This is usually done when the subclass has no object properties. Any object properties it
or a further subclass does have can always be accessed with "get_property" and
"set_property" (together with "find_property" and "list_properties" to enquire about
them).
Generic code for any object subclass can use the names "get_property" and "set_property"
to be sure of getting the object properties as such.
HIERARCHY
Glib::Object
METHODS
object = $class->new (...)
• ... (list) key/value pairs, property values to set on creation
Instantiate a Glib::Object of type $class. Any key/value pairs in ... are used to set
properties on the new object; see "set". This is designed to be inherited by Perl-derived
subclasses (see Glib::Object::Subclass), but you can actually use it to create any
GObject-derived type.
scalar = Glib::Object->new_from_pointer ($pointer, $noinc=FALSE)
• $pointer (unsigned) a C pointer value as an integer.
• $noinc (boolean) if true, do not increase the GObject's reference count when creating
the Perl wrapper. this typically means that when the Perl wrapper will own the
object. in general you don't want to do that, so the default is false.
Create a Perl Glib::Object reference for the C object pointed to by $pointer. You should
need this very rarely; it's intended to support foreign objects.
NOTE: the cast from arbitrary integer to GObject may result in a core dump without
warning, because the type-checking macro G_OBJECT() attempts to dereference the pointer to
find a GTypeClass structure, and there is no portable way to validate the pointer.
unsigned = $object->get_data ($key)
• $key (string)
Fetch the integer stored under the object data key $key. These values do not have types;
type conversions must be done manually. See "set_data".
$object->set_data ($key, $data)
• $key (string)
• $data (scalar)
GObject provides an arbitrary data mechanism that assigns unsigned integers to key names.
Functionality overlaps with the hash used as the Perl object instance, so we strongly
recommend you use hash keys for your data storage. The GObject data values cannot store
type information, so they are not safe to use for anything but integer values, and you
really should use this method only if you know what you are doing.
pspec or undef = $object_or_class_name->find_property ($name)
• $name (string)
Find the definition of object property $name for $object_or_class_name. Return "undef" if
no such property. For the returned data see Glib::Object::list_properties.
$object->freeze_notify
Stops emission of "notify" signals on $object. The signals are queued until "thaw_notify"
is called on $object.
$object->get (...)
• ... (list) list of property names
Alias for "get_property" (see "get and set" above).
$object->set (key => $value, ...)
• ... (list) key/value pairs
Alias for "set_property" (see "get and set" above).
list = $object_or_class_name->list_properties
List all the object properties for $object_or_class_name; returns them as a list of
hashes, containing these keys:
name
The name of the property
type
The type of the property
owner_type
The type that owns the property
descr
The description of the property
flags
The Glib::ParamFlags of the property
$object->notify ($property_name)
• $property_name (string)
Emits a "notify" signal for the property $property on $object.
gpointer = $object->get_pointer
Complement of "new_from_pointer".
$object->get_property (...)
Fetch and return the values for the object properties named in ....
$object->set_property (key => $value, ...)
Set object properties.
unsigned = $object_or_class_name->signal_add_emission_hook ($detailed_signal, $hook_func,
$hook_data=undef)
• $detailed_signal (string) of the form "signal-name::detail"
• $hook_func (subroutine)
• $hook_data (scalar)
Add an emission hook for a signal. The hook will be called for any emission of that
signal, independent of the instance. This is possible only for signals which don't have
the "G_SIGNAL_NO_HOOKS" flag set.
The $hook_func should be reference to a subroutine that looks something like this:
sub emission_hook {
my ($invocation_hint, $parameters, $hook_data) = @_;
# $parameters is a reference to the @_ to be passed to
# signal handlers, including the instance as $parameters->[0].
return $stay_connected; # boolean
}
This function returns an id that can be used with "remove_emission_hook".
Since 1.100.
list = $instance->signal_chain_from_overridden (...)
• ... (list)
Chain up to an overridden class closure; it is only valid to call this from a class
closure override.
Translation: because of various details in how GObjects are implemented, the way to
override a virtual method on a GObject is to provide a new "class closure", or default
handler for a signal. This happens when a class is registered with the type system (see
Glib::Type::register and Glib::Object::Subclass). When called from inside such an
override, this method runs the overridden class closure. This is equivalent to calling
$self->SUPER::$method (@_) in normal Perl objects.
unsigned = $instance->signal_connect ($detailed_signal, $callback, $data=undef)
• $detailed_signal (string)
• $callback (subroutine)
• $data (scalar) arbitrary data to be passed to each invocation of callback
Register callback to be called on each emission of $detailed_signal. Returns an
identifier that may be used to remove this handler with
"$object->signal_handler_disconnect".
unsigned = $instance->signal_connect_after ($detailed_signal, $callback, $data=undef)
• $detailed_signal (string)
• $callback (scalar)
• $data (scalar)
Like "signal_connect", except that $callback will be run after the default handler.
unsigned = $instance->signal_connect_swapped ($detailed_signal, $callback, $data=undef)
• $detailed_signal (string)
• $callback (scalar)
• $data (scalar)
Like "signal_connect", except that $data and $object will be swapped on invocation of
$callback.
retval = $object->signal_emit ($name, ...)
• $name (string) the name of the signal
• ... (list) any arguments to pass to handlers.
Emit the signal name on $object. The number and types of additional arguments in ... are
determined by the signal; similarly, the presence and type of return value depends on the
signal being emitted.
$ihint = $instance->signal_get_invocation_hint
Get a reference to a hash describing the innermost signal currently active on $instance.
Returns undef if no signal emission is active. This invocation hint is the same object
passed to signal emission hooks, and contains these keys:
signal_name
The name of the signal being emitted.
detail
The detail passed on for this emission. For example, a "notify" signal will have the
property name as the detail.
run_type
The current stage of signal emission, one of "run-first", "run-last", or "run-
cleanup".
$object->signal_handler_block ($handler_id)
• $handler_id (unsigned)
$object->signal_handler_disconnect ($handler_id)
• $handler_id (unsigned)
boolean = $object->signal_handler_is_connected ($handler_id)
• $handler_id (unsigned)
$object->signal_handler_unblock ($handler_id)
• $handler_id (unsigned)
integer = $instance->signal_handlers_block_by_func ($func, $data=undef)
• $func (subroutine) function to block
• $data (scalar) data to match, ignored if undef
integer = $instance->signal_handlers_disconnect_by_func ($func, $data=undef)
• $func (subroutine) function to block
• $data (scalar) data to match, ignored if undef
integer = $instance->signal_handlers_unblock_by_func ($func, $data=undef)
• $func (subroutine) function to block
• $data (scalar) data to match, ignored if undef
scalar = $object_or_class_name->signal_query ($name)
• $name (string)
Look up information about the signal $name on the instance type $object_or_class_name,
which may be either a Glib::Object or a package name.
See also "Glib::Type::list_signals", which returns the same kind of hash refs as this
does.
Since 1.080.
$object_or_class_name->signal_remove_emission_hook ($signal_name, $hook_id)
• $signal_name (string)
• $hook_id (unsigned)
Remove a hook that was installed by "add_emission_hook".
Since 1.100.
$instance->signal_stop_emission_by_name ($detailed_signal)
• $detailed_signal (string)
$object->thaw_notify
Reverts the effect of a previous call to "freeze_notify". This causes all queued "notify"
signals on $object to be emitted.
boolean = Glib::Object->set_threadsafe ($threadsafe)
• $threadsafe (boolean)
Enables/disables threadsafe gobject tracking. Returns whether or not tracking will be
successful and thus whether using perl ithreads will be possible.
$object->tie_properties ($all=FALSE)
• $all (boolean) if FALSE (or omitted) tie only properties for this object's class, if
TRUE tie the properties of this and all parent classes.
A special method available to Glib::Object derivatives, it uses perl's tie facilities to
associate hash keys with the properties of the object. For example:
$button->tie_properties;
# equivilent to $button->set (label => 'Hello World');
$button->{label} = 'Hello World';
print "the label is: ".$button->{label}."\n";
Attempts to write to read-only properties will croak, reading a write-only property will
return '[write-only]'.
Care must be taken when using tie_properties with objects of types created with
Glib::Object::Subclass as there may be clashes with existing hash keys that could cause
infinite loops. The solution is to use custom property get/set functions to alter the
storage locations of the properties.
SIGNALS
notify (Glib::Object, Glib::ParamSpec)
SEE ALSO
Glib
COPYRIGHT
Copyright (C) 2003-2011 by the gtk2-perl team.
This software is licensed under the LGPL. See Glib for a full notice.